This invention relates to an apparatus for bending and hemming a metal panel into an automotive body closure member such as a tailgate.
An automotive body panel closure member such as a tailgate generally comprises both an inner panel and an outer panel that may be formed from a single sheet of material such as sheet metal. To form such a body panel, the sheet must be folded upon itself, i.e., xe2x80x9cdoubled-overxe2x80x9d and the mating edges joined to provide a finished and structurally sound component for use on a vehicle. One well-known process for joining the edges of such a panel is known in the art as hemming and is accomplished using a hemming machine that folds the edge of one panel over the edge of the other panel to mechanically lock the panel edges together.
The invention is a bending and hemming apparatus comprising a bending machine configured to support a metal panel workpiece at a bending station and to bend the metal panel workpiece until the metal panel workpiece is doubled-over such that opposite mating edges of the panel are brought together and generally aligned in preparation for hemming. The apparatus includes a hemming machine configured to hem at least one mating edge of the metal panel workpiece. The hemming machine is configured to hem at least one mating edge of a metal panel workpiece while the workpiece is still supported on the bending machine at the bending station to obviate the need to transport the workpiece from the bending station to a separate hemming station following bending.
According to another aspect of the invention, a method is provided for both bending and hemming a metal panel workpiece. The method includes loading a metal panel workpiece onto a bending machine and moving an anvil assembly into a position to act as a fulcrum for subsequent bending of the workpiece. The workpiece is then bent a predetermined number of degrees around an anvil tool portion of the anvil assembly by rotating a movable die element of the bending machine the predetermined number of degrees until the metal panel workpiece is doubled-over such that mating edges of the panel are brought together and generally aligned. A finished part is then formed from the workpiece by actuating the hemming machine to hem at least a portion of a mating edge of the workpiece. The bending machine and hemming machine are then actuated to release the finally hemmed part.
Objects, features and advantages of this invention include the ability to bend and hem the edge of a sheet metal workpiece at a single work station, and to pre-hem the edge of a sheet metal workpiece at the same work station where initial bending and hemming occur.